GMS90C320
OCT. 2000 Ver 1.2
31
AC Characteristics for 24MHz
External Data Memory Characteristics
Advance Information (24MHz)
External Clock Drive
Parameter
Symbol
24 MHz Oscillator
Variable Oscillator
1/t
C LCL
= 3.5 to 24MHz
Unit
Min.
Max.
Min.
Max.
RD pulse width
t
R LR H
180
-
6t
C LC L
-70
-
ns
WR pulse width
t
W LW H
180
-
6t
C LC L
-70
-
ns
Address hold after ALE
t
LLA X 2
56
-
2t
C LC L
-27
-
ns
RD to valid data in
t
R LD V
-
118
-
5t
C LC L
-90
ns
Data hold after RD
t
R H D X
0
-
0
-
ns
Data float after RD
t
R H D Z
-
63
-
2t
C LC L
-20
ns
ALE to valid data in
t
LLD V
-
200
-
8t
C LC L
-133
ns
Address to valid data in
t
A VD V
-
220
-
9t
C LC L
-155
ns
ALE to WR or RD
t
LLW L
75
175
3t
C LC L
-50
3t
C LC L
+50
ns
Address valid to WR or RD
t
A VW L
67
-
4t
C LC L
-97
-
ns
WR or RD high to ALE high
t
W H LH
17
67
t
C LC L
-25
t
C LC L
+25
ns
Data valid to WR transition
t
Q VW X
5
-
t
C LC L
-37
-
ns
Data setup before WR
t
Q VW H
170
-
7t
C LC L
-122
-
ns
Data hold after WR
t
W H Q X
15
-
t
C LC L
-27
-
ns
Address float after RD
t
R LA Z
-
0
-
0
ns
Table 11.
Parameter
Symbol
Variable Oscillator
(Freq. = 3.5 to 24MHz)
Unit
Min.
Max.
Oscillator period
t
C LC L
41.7
285.7
ns
High time
t
C H C X
12
t
C LC L
- t
C LC X
ns
Low time
t
C LC X
12
t
C LC L
- t
C H C X
ns
Rise time
t
C LC H
-
12
ns
Fall time
t
C H C L
-
12
ns
